In a networked embedded system, detecting or locating error and/or diagnostic data relevant to a component can be very time-consuming and labor-intensive. This applies in particular when all the components have their own data store in which they store their relevant information or data, for example status data, error data or general operating information.
In the case of malfunctions or faults or a total failure of components in the network or in the networked embedded system it is usually difficult or even impossible to gain access to error and/or diagnostic data relevant to some or all of the affected components. This makes diagnosing the error very complicated, labor-intensive and time-consuming. This is the case above all when storage facilities containing the error and/or diagnostic data relevant to components (such as e.g. status data, error or fault information) or their interfaces are defective.
In order to determine the causes of a fault, to locate errors and/or to establish a corresponding diagnosis it is important to be able to record and analyze information relating to the affected or relevant components of the networked embedded system. Due to a failure of connections between the components or in the event of failure of the components themselves it becomes impossible in the existing networked embedded systems to read out from the system any information present that is necessary for locating errors or for establishing a diagnosis.
The generally known networked embedded systems usually offer the following two approaches for storing error and/or diagnostic data which is relevant to components of the networked embedded system and can be drawn upon for analysis and for establishing a diagnosis in the event of a fault or an error in the networked embedded system.
One possibility is the use of centralized solutions for storing error and/or diagnostic data relating to the components of a networked embedded system. The individual components send their current data or information to a central storage facility. Said storage facility must be implemented as permanently available and failsafe, especially in safety-critical systems such as, for example, installations for controlling chemical processes. This is technically very complicated and expensive, however. But in non-safety-critical manufacturing plants too, a huge investment of resources is necessary with regard to the fault tolerance of the error store, since long diagnosis times result in production downtimes, which in turn is very expensive. If the connection between the components of the networked embedded system and the centralized storage facility fails, it is no longer possible to gain access to the data or information that may be relevant to locating a fault or error that has occurred and/or to establishing a diagnosis.
In a further approach, the error and/or diagnostic data is stored in the component itself, as already indicated hereintofore. This is the case, for example, in systems designed for engine management of cars, where the error data is stored in the respective component itself. In the case of a total failure of a component the error store can no longer be accessed. This makes error diagnosis impossible. The consequence is that the entire component has to be replaced. This leads to a successful outcome only if the cause of the error or fault lay directly in the replaced component. If, however, the cause for the failure of the replaced component lay in a malfunction of a further component indirectly or directly connected to the replaced component, this will result in recurrent failures of the replaced component since the cause of the error could not be identified with certainty. No full diagnosis could therefore be made. Consequently no complete elimination of the error is guaranteed.